diff options
| author | Matt Johnston <matt@codeconstruct.com.au> | 2022-02-22 12:17:38 +0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2022-02-23 12:29:15 +0000 |
| commit | dc121c0084910db985cf1c8ba6fce5d8c307cc02 (patch) | |
| tree | d9a2d56d1ded9a273b032beb317d36ea86ffb6f3 /net/mctp/test/utils.c | |
| parent | 4767b7e2ed818e97851d236d23f2e2ffa90af6ec (diff) | |
mctp: make __mctp_dev_get() take a refcount hold
Previously there was a race that could allow the mctp_dev refcount
to hit zero:
rcu_read_lock();
mdev = __mctp_dev_get(dev);
// mctp_unregister() happens here, mdev->refs hits zero
mctp_dev_hold(dev);
rcu_read_unlock();
Now we make __mctp_dev_get() take the hold itself. It is safe to test
against the zero refcount because __mctp_dev_get() is called holding
rcu_read_lock and mctp_dev uses kfree_rcu().
Reported-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Matt Johnston <matt@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/mctp/test/utils.c')
| -rw-r--r-- | net/mctp/test/utils.c | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/net/mctp/test/utils.c b/net/mctp/test/utils.c index 7b7918702592..e03ba66bbe18 100644 --- a/net/mctp/test/utils.c +++ b/net/mctp/test/utils.c @@ -54,7 +54,6 @@ struct mctp_test_dev *mctp_test_create_dev(void) rcu_read_lock(); dev->mdev = __mctp_dev_get(ndev); - mctp_dev_hold(dev->mdev); rcu_read_unlock(); return dev; |